malachite (w. chalcocite (?), dolomite and quartz)

TSNB785
Specimen
Palache, C.
Exhibit 1. Malachite (w. chalcocite (?), dolomite and quartz); 157 mm.
Exhibit 1. Malachite (w. chalcocite (?), dolomite and quartz); 157 mm.
Image Credit: Malcolm Southwood
Exhibit 2. 70 mm field of view.
Exhibit 2. 70 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 3. Specimen label (Shaler Memorial Expedition).
Exhibit 3. Specimen label (Shaler Memorial Expedition).
Image Credit: MGMH Archive
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Specimen Title

malachite (w. chalcocite (?), dolomite and quartz)

Associated Minerals

azurite; chalcocite (?); dolomite; quartz; undetermined

Principal Mineral

Malachite

Size

Cabinet; 157mm

Location in the Mine

First oxidation zone; 7 Level; East

Provenance

Palache, C.

Collection

MGMH; 146393

Entry Number

Specimen; TSNB785

Description

A mineralised fragment of silicified dolostone breccia, cut by a vein of quartz and dolomite. The vein contains clasts of sooty-grey chalcocite (?) with alteration rims of malachite where they contact the dolomite (Exhibit 2). Other secondary minerals are also present on the specimen – minor azurite staining and a few small vugs of pistachio-green Cu/Pb arsenates (not identified).


The specimen is not aesthetic but it is significant for its paragenesis and provenance.


This specimen was collected by Charles Palache of Harvard University, on 7 April, 1922 during an underground visit at Tsumeb at the time of the Shaler Memorial Expedition to South Africa. It carries a Shaler Expedition label (Exhibit 3) with a field number – 13944 – in addition to its MGMH catalogue number.